TFT-LCD背板设计对线残像改善的研究

线残像一直是TFT-LCD行业中一个重点改善的不良之一。为了解决该不良,本文通过对不同样品进行线残像评价及测试公共电极电压的畸变情况,从TFT-LCD背板设计方面研究了公共电极电压的畸变对线残像的影响。首先,通过激光熔接的方法将屏内的公共电极电压信号引出,然后测出在信号线电压作用下的公共电极电压发生畸变的幅值,最后将该幅值和实测的线残像水平进行了对比,同时对不同信号线数量、信号线和公共电极的交叠面积、信号线与公共电极的距离、外围电路补偿等相关设计的测试和研究。结果表明:公共电极电压的畸变程度与线残像水平具有对应性;信号线数量与公共电极电压畸变幅值成比例关系;信号线与公共电极线的单位交叠面积从66μm~2降到37μm~2时,其公共电极电压畸变程度降低了63%;增大公共电极与信号线之间的距离有助于改善甚至消除线残像,当距离从1.49μm增大到2.39μm时,公共电极电压畸变幅值减小了28%。通过降低信号线数量、降低信号线和公共电极线的交叠面积、增大信号线和公共电极的距离、外围电路补偿等方案均可改善线残像水平,对TFT-LCD画面显示品质的提高具有重要指导意义。

Investigation on the improvement of line image sticking by array mask design of TFT-LCD

Line image sticking is one of issue all along which needs to be improved in TFT-LCD industry. In order to solve this problem, the evaluation of line image sticking level and the common voltage(V_com) distortion of different productions were tested, and the effect of Vcom distortion on line image sticking was investigate in the aspect of array mask design. First of all, laser wedding was used to help us to test the signal of V_com in panel, then the V_com distortion could be tested when data voltage was inputted. Finally the V_com distortion and line image sticking level were compared, in the meantime, number of data line, the overlap area between data line and Common line, the distance between data line and Common electrode and circuit compensation which are related to array mask design were analyzed. The result suggests that V_com distortion corresponds to line image sticking level; V_com distortion increases with the number of data line; V_com distortion decreases by 63% when the overlap of data line and Common line decreases from 66 μm² to 37 μm²; Increasing the distance between data line and common electrode can improve line image sticking, V_com distortion decreases by 28% when distance increases from 1.49 μm to 2.39 μm. Decreasing the number of data line, decreasing the overlap area between data line and Common line, increasing the distance between data line and Common electrode and circuit compensation were considered to be effective to improve line image sticking, which is of vital importance for the image quality of TFT-LCD.